A radio access technology of a wireless cellular mobile network is developing continuously, and an objective of the radio access technology is to meet user requirements for a higher rate, wider coverage, and a larger capacity in the future. Currently, the technology is evolving from a 3G system to long term evolution (LTE) system, and is further evolving to an LTE-Advanced system. In an LTE system, a network sends, by using radio resource control protocol (Radio Resource Control, RRC) signaling, measurement configuration information to UE that is in a connected state; and the UE performs measurement according to content of the measurement configuration information, and then reports a measurement result to the network. If a primary frequency of a target cell is the same as a primary frequency of a serving cell of the UE, measurement of the UE is referred to as intra-frequency measurement; if a primary frequency of a target cell is different from a primary frequency of a serving cell of the UE, measurement of the UE is referred to as inter-frequency measurement. When performing the inter-frequency measurement, the UE may need to adjust a radio frequency to a location in which the frequency is located. Consequently, data cannot be sent or received on a serving frequency.
UE generally has only one receiver, and therefore can receive a signal on only one frequency at a time. Before inter-frequency inter-system handover is performed, inter-frequency measurement needs to be performed first. Therefore, a measurement gap (GAP), that is, a period of time in which the UE leaves a current frequency and performs measurement on another frequency, is required. When the inter-frequency measurement is performed, an eNB configures an inter-frequency measurement gap (GAP), which is specifically determined by two parameters, that is, a gap pattern and a gap offset (gapOffset). LTE supports two gap patterns, that is, a pattern 0 and a pattern 1. Measurement gap repetition periods (MGRP) of the pattern 0 and the pattern 1 are respectively 40 ms and 80 ms. A start location of each GAP, that is, a system frame number (SFN) and a subframe number (subframe), meets the following relationship:SFN mod T=FLOOR(gapOffset/10);subframe=gapOffset mod 10;where T=MGRP/10.
Measurement GAP lengths are uniformly defined as 6 ms. To synchronize with a measured target cell, at least the following is needed: frequency handover duration (1 ms) of a receiver+(duration of primary and secondary synchronization signals+signal measurement duration) (5 ms), which are about 6 ms. After receiving information of a gap pattern and a gap offset from the eNB, the UE calculates, according to the foregoing formula, a start point of a subframe location for the inter-frequency measurement; and performs the inter-frequency measurement on six consecutive subframes starting from a start subframe. The UE neither receives data transmitted over a physical downlink control channel (PDCCH) nor sends uplink data in a gap location. Therefore, a network does not schedule the UE in a GAP period.
Currently, dual connectivity (DC) is being discussed, that is, user equipment (UE) may simultaneously connect to a master eNodeB (MeNB) and a secondary eNodeB (SeNB) to transmit data, thereby improving a throughput of the UE. In a dual connectivity scenario, a case in which a scheduling resource is wasted occurs.